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Penicillin antibiotics (PENs) play an important role in killing pathogenic bacteria. However, the residues of various penicillin antibiotics in milk gradually accumulate in the human body with the increase of milk intake, which causes direct harm to the human body. Aptamers can be used as recognition element of sensors. It is great significance to use broad-spectrum aptamers for simultaneous detection of PENs. In this study, we reported the screening and identification of DNA aptamers for PENs. The aptamers were screened by graphene oxide-systematic evolution of ligands by exponential enrichment (GO-SELEX). The broad-spectrum aptamers with high affinity and specificity were successfully obtained after 13 rounds of screening. The affinity and specificity of candidate aptamers were analyzed by a GO fluorescence competition method. Further sequence analysis revealed that a truncated 47 nt aptamer (P-11-1) had a higher affinity than the original 79 nt aptamer. The truncated aptamer P-11-1 was used as a recognition element, and an electrochemical aptasensor was prepared using gold nanoparticles (AuNPs) combined with ferroferric oxide-multi walled carbon nanotube (Fe3O4-MWCNTs) complex. The results showed that the developed aptasensor achieved the simultaneous detection of PENs in milk samples across a concentration range of 2 nM-10,000 nM, achieving a limit of detection of 0.667 nM. This methodology provided a simple and sensitive new thinking for antibiotic multi-residue detection.
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Aptámeros de Nucleótidos , Técnicas Biosensibles , Nanopartículas del Metal , Humanos , Animales , Leche/química , Penicilinas/análisis , Oro/química , Nanopartículas del Metal/química , Aptámeros de Nucleótidos/química , Técnica SELEX de Producción de Aptámeros/métodos , Técnicas Biosensibles/métodos , Límite de DetecciónRESUMEN
To effectively monitor multi-residues of penicillin antibiotics (PENs) in milk, we developed a novel ratiometric electrochemical aptasensor enabling simultaneous detection of PENs. The aptasensor employed a broad-spectrum aptamer as a recognition element, niobium carbide functionalized with methylene blue (Nb2C-MB) as a reference signal generator, and a ferrocene-labeled aptamer (Fc-Apt) as an output signal. Electrodes were modified with Fe-N-C doped carbon nanotubes (Fe-N-C-CNTs) to amplify detection signals further. During detection, Fc-Apt binding to PENs decreased Fc current intensity (IFc) and increased MB current intensity (IMB). The simultaneous detection of PENs was achieved using IMB/IFc as a quantitative signal. Under optimal conditions, a good linear relationship between IMB/IFc and antibiotic concentration was observed, indicating the aptasensor had a robustness. The limits of detection of aptasensor for four penicillin antibiotics and their mixed targets were 0.093-0.191 nM. This work provides a new approach to multi-residue detection of the same class of antibiotics.
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Antibacterianos , Aptámeros de Nucleótidos , Técnicas Biosensibles , Técnicas Electroquímicas , Contaminación de Alimentos , Leche , Penicilinas , Leche/química , Aptámeros de Nucleótidos/química , Animales , Antibacterianos/análisis , Antibacterianos/química , Penicilinas/análisis , Penicilinas/química , Contaminación de Alimentos/análisis , Límite de Detección , Residuos de Medicamentos/análisis , Residuos de Medicamentos/química , BovinosRESUMEN
This research aimed to combine serum NLR-pyrin domain containing 1 (NLRP1) levels and collateral circulation to assess ischemic stroke patients and predict the prognoses of the patients. This present prospective observational study enrolled 196 ischemic stroke patients. All patients underwent CTA as well as digital subtraction angiography (DSA) to assess collateral circulation by American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR). In addition, we collected serum samples from 100 patients with carotid atherosclerosis as controls. The serum NLRP1, tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-1ß and C-reactive protein (CRP) levels were measured by enzyme-linked immunosorbent assay (ELISA). The age, BMI, sex, smoke condition, diastolic blood pressure, systolic blood pressure, National Institutes of Health Stroke Scores (NIHSS), modified Rankin Scale (mRS) scores, imaging indicators and the levels of triglyceride, total cholesterol (TC), low-density leptin cholesterol (LDLC), high-density leptin cholesterol of all subjects were recorded. All data used SPSS 18.0 to statistical analyses. The serum levels of NLRP1 were remarkably enhanced in the ischemic stroke patients compared with the carotid atherosclerosis patients. The NIHSS score, the mRS score after 90 days and the levels of NLRP1, CRP, TNF-α IL-6 and IL-1ß of ischemic stroke patients in the ASITN/SIR grade 0 to 2 group were remarkably elevated than the ischemic stroke patients in ASITN/SIR grade 3 to 4 group. Spearman analysis supported that a positive correlation existed among the NLRP1, CRP, IL-6, TNF-α, and IL-1ß levels. The NIHSS score, infarct volume and the levels of NLRP1, IL-6, TNF-α, and IL-1ß of ischemic stroke patients in the mRS score ≥ 3 group were remarkably elevated than the ischemic stroke patients in the mRS score ≤ 2 group. ASITN/SIR grade and NLRP1 could be potential diagnostic biomarkers of poor prognosis of ischemic stroke patients. It was found that NLRP1, ASITN/SIR grade, infarct volume, NIHSS, IL-6, and IL-1ß were the risk factors for bad prognosis of ischemic stroke patients. This study showed that the serum NLRP1 levels were remarkably decreased in ischemic stroke patients. In addition, the serum NLRP1 levels and ASITN/SIR grade could predict the prognosis of ischemic stroke patients.
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Isquemia Encefálica , Enfermedades de las Arterias Carótidas , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Leptina , Circulación Colateral/fisiología , Relevancia Clínica , Interleucina-6 , Factor de Necrosis Tumoral alfa , Angiografía por Tomografía Computarizada/métodos , Infarto , Colesterol , Isquemia Encefálica/terapia , Proteínas NLRRESUMEN
In this work, we report on the spectroscopy and dynamics of the quasi-linear S(2) state of chlorocarbene, CHCl, and its deuterated isotopologue using optical-optical double resonance (OODR) spectroscopy through selected rovibronic levels of the S(1) state. This study, which represents the first observation of the S(2) state in CHCl, builds upon our recent examination of the corresponding state in CHF, where pronounced mode specificity was observed in the dynamics, with predissociation rates larger for levels containing bending excitation. In the present work, a total of 14 S(2) state vibrational levels with angular momentum l = 1 were observed for CHCl, and 34 levels for CDCl. The range of l in this case was restricted by the pronounced Renner-Teller effect in the low-lying S(1) levels, which severely reduces the fluorescence lifetime for levels with K(a) > 0. Nonetheless, by exploiting different intermediate S(1) levels, we observed progressions involving all three fundamental vibrations. For levels with long predissociation lifetimes, rotational constants were determined by measuring spectra through different intermediate J levels of the S(1) state. Plots of the predissociation linewidth (lifetime) vs. energy for various S(2) levels show an abrupt onset, which lies near the calculated threshold for elimination to form C((3)P) + HCl on the triplet surface. Our experimental results are compared with a series of high level ab initio calculations, which included the use of a dynamically weighted full-valence CASSCF procedure, focusing maximum weight on the state of interest (the singlet and triplet states were computed separately). This was used as the reference for subsequent Davidson-corrected MRCI(+Q) calculations. These calculations reveal the presence of multiple conical intersections in the singlet manifold.
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Metano/análogos & derivados , Metano/química , Teoría Cuántica , EspectrofotometríaRESUMEN
BACKGROUND: Polycystic ovary syndrome (PCOS) patients are prone to early pregnancy loss. Studies have found that the blood fibrinolytic activity of PCOS patients is closely related to the high abortion rate. At present, it is considered that the combination of traditional Chinese and Western medicine in the treatment of PCOS with threatened abortion has a good effect on fetal protection. Therefore, the clinical efficacy of the combination of traditional Chinese and Western medicine in the treatment of PCOS with threatened abortion was systematically evaluated, and the effect of traditional Chinese medicine on the blood fibrinolytic status of patients was also evaluated. METHODS: The clinical randomized controlled trials (RCTs) of integrated traditional Chinese and Western medicine in the treatment of PCOS with threatened abortion were reviewed from four Chinese databases (CNKI, WANFANG, VIP, and SINOMED) and two English databases (PubMed, EMBASE) from their time of establishment to May 2021. According to the inclusive and exclusive criteria, tests were selected, data were extracted and evaluated, the systematic review was carried out by description analysis, and the meta-analysis was conducted using RevMan 5.3 software from Cochrane Collaboration. Begg's and Egger's tests were performed for assessing symmetries of funnel plot by the software Stata 16.0. RESULTS: 6 RCTs involving 361 participants were included. Meta-analysis results showed that integrated traditional Chinese and Western medicine can increase the total efficacy compared with the control groups [RR=1.22, 95% CI (1.10, 1.35), P=0.0002]. Meanwhile, the improvement of TCM syndrome integral [MD=-2.11, 95% CI (-2.56, -1.66), P<0.00001], D-II [MD=-0.29, 95% CI (-0.49, -0.09), P=0.004], Hcy [MD=-3.02, 95% CI (-3.64, -2.39, P=0.00001], PAI-I [SMD=-2.38, 95% CI (-2.82, -1.73), P<0.00001] were better than a single Western medicine treatment. And it can increase the level of ß-HCG [SMD=3.44, 95% CI (1.87, 5.01), P<0.0001], P [MD=7.70, 95% CI (7.10, 8.31), P<0.00001], E2 [MD=205.36, 95% CI (140.93, 269.80), P<0.00001]. The funnel plot, Egger's test (P=0.210), and Begge's test (P=0.573) suggested that there was no evidence of substantial publication bias. CONCLUSIONS: The effect of integrated traditional Chinese and Western medicine is better than that of Western medicine alone in the treatment of PCOS with threatened abortion, and it has certain advantages in improving the fibrinolytic status of patients. However, due to the limitation of the quality and quantity of the included literature, more rigorous and larger sample studies are needed to confirm these conclusions in the future.
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In this work, we report on our full results of the spectroscopic analysis of the quasi-linear S(2) state of the prototypical halocarbene, CHF, and its deuterated isotopomer CDF using optical-optical double resonance spectroscopy through the S(1) state. A total of 51 S(2) state vibrational levels with angular momenta in the range [script-l] = 0-3 were observed for CHF, and 76 levels for CDF. Progressions involving all three fundamental vibrations were observed, and rotational constants were determined for each of these levels by measuring spectra through different intermediate J levels of the S(1) state. Our experimental results are in excellent agreement with the predictions of vibrational calculations using the discrete variable representation method. The variational vibrational calculations were performed with an analytic potential energy surface fit to ab initio data by the method of interpolating moving least squares. The ab initio data are Davidson-corrected multi-reference configuration interaction calculations based on a state-averaged multiconfigurational self-consistent field reference incorporating a generalized dynamic weighting scheme.
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In this work, we report on our full results of the dynamics of the quasi-linear, predissociated S(2) state of the prototypical halocarbene, CHF, and its deuterated isotopomer CDF using optical-optical double resonance spectroscopy through the S(1) state. Homogeneous linewidths were determined for a total of 51 S(2) state vibrational levels with angular momenta in the range [script-l] = 0-3 for CHF, and 76 levels for CDF. Progressions involving all three fundamental vibrations were observed. The linewidth data reveal pronounced mode specificity for both CHF and CDF, where pure bending states have the largest linewidths. For CDF, the linewidths are uniformly narrower. Calculated (CCSD(T)/aug-cc-pVQZ//MP2/aug-cc-pVQZ) stationary points on the CHF potential energy surface show that two dissociative pathways are available at the energies accessed in this experiment: dissociation on the triplet surface, over a barrier, to form C((3)P) + HF, and dissociation to ground state CF + H products. The former is excluded as a primary channel based on the small spin-orbit coupling in this system. A 27-state dynamically weighted full-valence complete active space self-consistent field calculation was performed with maximal weight focused on the S(2) state, which was then used as a reference for Davidson-corrected multireference configuration interaction calculations MRCI(+Q) of the three lowest A(') and two lowest A(") states. These calculations reveal the presence of multiple conical intersections in the singlet manifold. Consistent with our experimental results, the most important of these involves the repulsive S(3) state, which conically intersects with S(2) at linearity.
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PURPOSE: The aim of this study was to evaluate the benefits and harms of primary closure versus T-tube drainage after common bile duct (CBD) exploration for choledocholithiasis. METHODS: A literature search of MEDLINE (PubMed), EMBASE, and the Cochrane Library was done to identify randomized controlled trials assessing the benefits and harms of primary closure versus T-tube drainage after CBD exploration from Jan. 1990 to Apr. 2010. A meta-analysis was set up to distinguish overall difference between the primary closure and the T-tube drainage group. RESULTS: There were statistically significant differences between groups: biliary complications (odds ratio (OR) 95% confidence interval (CI), 0.42 (0.19-0.92); P = 0.03), main complications (OR 95% CI, 0.46 (0.23-0.90); P = 0.02), operating time (weighted mean difference (WMD) 95% CI, -19.53 (-29.35 to -9.71); P < 0.0001), and hospital stay (WMD 95% CI, -4.16 (-7.07 to -1.24); P = 0.005) except peri-operative mortality (OR 95% CI, 0.83 (0.11-6.37); P = 0.86), residual stones (OR 95% CI, 0.70 (0.22-2.25); P = 0.55), and abdominal collections (OR 95% CI, 1.93 (0.34-10.76); P = 0.46). And the result of wound infection (OR 95% CI, 0.38 (0.14-1.02); P = 0.05) tended to favor the primary closure group. CONCLUSION: The primary closure might be as effective as T-tube drainage after choledochotomy in the prevention of the development of post-operative complications.
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Técnicas de Cierre de Herida Abdominal , Coledocostomía/métodos , Drenaje/métodos , Cálculos Biliares/cirugía , Complicaciones Posoperatorias/etiología , Cálculos Biliares/mortalidad , Mortalidad Hospitalaria , Humanos , Tiempo de Internación/estadística & datos numéricos , Complicaciones Posoperatorias/mortalidad , Ensayos Clínicos Controlados Aleatorios como Asunto , Análisis de Supervivencia , Técnicas de SuturaRESUMEN
PURPOSE: The aim of this study was to estimate efficacy of mechanical bowel preparation with polyethylene glycol (PEG) in prevention of postoperative complications in elective colorectal surgery. METHOD: A literature search of MEDLINE (PubMed), EMBASE, and the Cochrane Library was done to identify randomized controlled trials involving comparison of postoperative complications after mechanical bowel preparation with PEG (PEG group) and no preparation (control group). A meta-analysis was set up to distinguish overall difference between the two groups. RESULTS: A total of five randomized controlled trials was identified according to our inclusion criteria. The use of PEG for mechanical bowel preparation did not significantly reduce the rate of surgical site infection (SSI; odds ratio (OR) 95% confidence interval (CI), 1.39 (0.85-2.25); P = 0.19) including incisional SSI (OR 95% CI, 1.44 (0.88-2.33); P = 0.15), organ/space SSI (OR 95% CI, 1.10 (0.43-2.78); P = 0.49), anastomotic leak (OR 95% CI,1.78 (0.95-3.33; P = 0.07), mortality (OR 95% CI, 1.24 (0.37-4.14; P = 0.73), infectious complications (OR 95% CI, 1.14 (0.62-2.08); P = 0.67), and hospital stay (weighted mean difference 95% CI, 2.17 (-2.90-7.25); P = 0.40) except main complications (OR 95% CI, 1.76 (1.09-2.85); P = 0.02), of which the rate increased significantly in the PEG group. CONCLUSION: The use of mechanical bowel preparation with PEG does not significantly lower postoperative complications in elective colorectal surgery.
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Colon/cirugía , Procedimientos Quirúrgicos del Sistema Digestivo/efectos adversos , Polietilenglicoles/uso terapéutico , Complicaciones Posoperatorias/prevención & control , Recto/cirugía , Distribución de Chi-Cuadrado , Procedimientos Quirúrgicos del Sistema Digestivo/mortalidad , Procedimientos Quirúrgicos Electivos , Humanos , Tiempo de Internación , Oportunidad Relativa , Polietilenglicoles/efectos adversos , Complicaciones Posoperatorias/mortalidad , Cuidados Preoperatorios , Medición de Riesgo , Infección de la Herida Quirúrgica/etiología , Infección de la Herida Quirúrgica/prevención & control , Resultado del TratamientoRESUMEN
BACKGROUND: This study aims to explore the relationship between spleen arterial blood flow (SBF) with platelet count, spleen index (SPI) and the serum nitric oxide (NO) level of patients with liver cirrhosis and to investigate the role of SBF in the development of hypersplenism. METHODOLOGY: Platelet count, SPI, SBF and serum NO levels were evaluated in 100 patients with liver cirrhosis caused by hepatitis B with hypersplenism (cirrhosis group) and 30 healthy persons without hypersplenism (control group). RESULTS: Platelet count in cirrhosis group and control group was 57.0 +/- 25.6 x 109/L and 205.8 +/- 47.4 x 109/L (p = 0.000), SBF was 535.7 +/- 263.7 milmin and 172.2 +/- 66.9 ml/min (p = 0.000), and serum NO level was 98.51 +/- 23.06 micromol/L and 48.43 +/- 19.47 micromol/L (p = 0.000). Linear correlations were made between SBF and platelet count in cirrhosis group (r = -0.573, p = 0.000), SBF and SPI (r = 0.607, p = 0.01), SBF and serum NO level (r = 0.754, p = 0.000). Moreover, serum NO level increased as liver disease aggravated (82.50 +/- 15.04 pmol/L in Child grade A, 94.61 +/- 21.00 micromol/L in grade B and 116.83 +/- 18.03 micromol/L in grade C; grade A versus grade C, p = 0.003). CONCLUSION: The elevation of SBF may play an important role in the development of hypersplenism and disorders in vasoactive factors such as the serum NO caused by liver cirrhosis may play an important role in the elevation of SBF.
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Hiperesplenismo/fisiopatología , Arteria Esplénica/fisiología , Adulto , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Estudios de Casos y Controles , Femenino , Hepatitis B/complicaciones , Humanos , Hiperesplenismo/sangre , Hiperesplenismo/diagnóstico por imagen , Hiperesplenismo/etiología , Cirrosis Hepática/virología , Masculino , Persona de Mediana Edad , Óxido Nítrico/sangre , Recuento de Plaquetas , Índice de Severidad de la Enfermedad , Ultrasonografía DopplerRESUMEN
We report on the first detailed studies of the spectroscopy of an iodocarbene, measuring fluorescence excitation and emission spectra of the X1A' --> A1A'' system of :CHI and the deuterated isotopomer :CDI. Due to similar bending and C-I stretching frequencies in the upper state, fluorescence excitation spectra of :CHI show polyads composed of members of the 2(0)(n-x)3(0)x progressions with x = 0-3. For :CDI, only progressions with x = 0, 1 are observed. Extrapolation of the 20n term energies for both isotopomers to a common origin places the electronic origin of the X1A' --> A1A'' system near 10500 cm-1, in good agreement with theoretical predictions. Rotational analysis of the 16 observed bands for CHI and 13 observed bands for :CDI yields rotational constants for the upper and lower states that are also in good agreement with theory. To investigate the controversial issue of the ground state multiplicity of :CHI, we measured single vibronic level emission spectra from many A1A'' levels. These spectra show conclusively that the ground state is a singlet, as for both isotopomers the ã3A'' origin is observed, lying well above the origin of the X1A' state. At energies above the ã3A'' origin, the spin-orbit mixing is so severe that few vibrational assignments can be made. Analysis of the emission spectra provides a lower limit on the singlet-triplet gap of 4.1 kcal mol-1, in excellent agreement with theoretical predictions.
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We report studies aimed at unraveling the complicated structure of the CCl 2 A (1)B 1 <-- X (1)A 1 system. We have remeasured the fluorescence excitation spectrum from approximately 17,500 to 24,000 cm (-1) and report the term energies and A rotational constants of many new bands for both major isotopologues (C (35)Cl 2, C (35)Cl (37)Cl). We fit the observed term energies to a polyad effective Hamiltonian model and demonstrate that a single resonance term accounts for much of the observed mixing, which begins approximately 1300 cm (-1) above the vibrationless level of the A (1)B 1 state. The derived A (1)B 1 vibrational parameters are in excellent agreement with ab initio predictions, and the mixing coefficients deduced from the polyad model fit are in close agreement with those derived from direct fits of single vibronic level (SVL) emission intensities. The approach to linearity and thus the Renner-Teller (RT) intersection is probed through the energy dependence of the A rotational constant and fluorescence lifetime measurements, which indicate a barrier height above the vibrationless level of the X (1)A 1 state of approximately 23,000-23,500 cm (-1), in excellent agreement with ab initio theory.
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We report on high resolution studies of spin-orbit mixing and the singlet-triplet gap in a prototypical halocarbene, CHCl, using stimulated emission pumping (SEP) spectroscopy from the A (1)A(") state. Results are reported for two isotopomers, CH(35)Cl and CD(35)Cl. We have obtained rotationally resolved spectra for the majority of X (1)A(') levels lying between 0 and 6000 cm(-1) above the zero-point level that were previously observed under low resolution in single vibronic level emission studies and several new levels that were previously unobserved or unresolved. In addition, SEP spectra were obtained for six a (3)A(") levels in CH(35)Cl and three levels in CD(35)Cl. The derived term energies and rovibrational parameters of the X (1)A(') and a (3)A(") states are in good agreement with theory. The a (3)A(") triplet spin-spin parameter is vibrational state dependent, and dominated by a second-order contribution from spin-orbit coupling with nearby X (1)A(') levels; it therefore provides a sensitive probe of spin-orbit mixing in this system. An analysis of three pairs of interactions between specific a (3)A(") and X (1)A(') levels in CH(35)Cl affords a pure electronic spin-orbit coupling element of 150 cm(-1), in good agreement with theoretical expectations. The derived singlet-triplet gaps, which are the most precise determined to date for any carbene, are compared with the predictions of high level ab initio theory.
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AIM: To explore the clinicopathological and molecular genetic features of hereditary nonpolyposis colorectal cancer (HNPCC) in Chinese population. METHODS: We collected 16 Chinese HNPCC families from Wenzhou, Zhejiang Province, China. Tumor tissues and peripheral white blood cells were studied using microdissection, microsatellite analysis, immunostaining of hMSH2 and hMLH1 proteins and direct DNA sequencing of hMSH2 and hMLH1 genes. RESULTS: (1) A total of 50 patients had CRC. Average age at diagnosis of the first CRC was 45.7 years; 40.9% and 28.7% of the CRCs were located proximal to the splenic flexure and in the rectum, respectively. Thirty-eight percent of the colorectal cancer patients had synchronous and metachronous CRC. 34.4% and 25% of the CRCs were poor differentiation cancer and mucinous adenocarcinoma, respectively. Fourteen extracoloni tumors were found, and the hepatic cancer was the most common tumor type. Twenty-one patients whose median survival time was 5.7 years died during 1-23 years. Twenty-nine patients have survived for 1-28 years, 58.6%, 41.4% and 24.1% patients have survived for more than 5, 10 and 15 years, respectively; (2) All nine tumor-tissues showed microsatellite instability (MSI) at more than two loci. Four tumor-tissues lost hMSH2 protein expression and one lost hMLH1 protein expression. Three pathological germline mutations were identified from five genetically analyzed families; two of three mutations had not been reported previously as they were a transition from C to A in exon 14 (codon 743) of hMSH2 and a TTC deletion in exon 14 (codon 530) of hMLH1. CONCLUSION: Chinese HNPCC have specific clinicopathological features, such as early onset, propensity to involve the proximal colon, and high frequency of multiple CRCs, liver cancer more frequent than endometrial cancer. Chinese HNPCC showed relatively frequent germline mutation of mismatch repair (MMR) genes that correlated closely with high-level MSI and loss of expression of MMR genes protein.
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Pueblo Asiatico/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/patología , Proteínas de Unión al ADN/genética , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Adaptadoras Transductoras de Señales , Adulto , Anciano , Secuencia de Bases , Proteínas Portadoras , China , Neoplasias Colorrectales Hereditarias sin Poliposis/etnología , Femenino , Mutación de Línea Germinal , Humanos , Inmunohistoquímica , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL , Proteína 2 Homóloga a MutS , Proteínas NuclearesRESUMEN
OBJECTIVE: To study the clinicopathological and molecular genetic characteristics of hereditary nonpolyposis colorectal cancer (HNPCC), to enable the early diagnosis and to evaluate the treatment. METHODS: We analyzed 12 families of HNPCC from Wenzhou, Zhejiang province, China. Mismatch repair genes hMSH2 and hMLH1 expression and microsatellite instability of tumor tissue were studied using microdissection, microsatellite analysis, immunohistochemical staining and Gene Scan analysis. Direct DNA sequencing of hMSH2 and hMLH1 were performed subsequently. RESULTS: Altogether 32 patients with colorectal cancer were recognized in 12 HNPCC families, with the median age of 45.2 years (75.0% before the age of 50 years). The proximal tumors accounted for 51.1%, while multiple colorectal cancers accounted for 34.4%. Poor differentiation cancers occupied half of the patients (53.1%). And 68.8% of the patients had the tumor of Dukes A and B. Among 12 HNPCC families, 7 cases in 6 HNPCC families developed extracolonic cancer. 13 cases died during follow up of 1 - 23 years. The median survival time was 6.4 years. 19 alive cases followed up from 1 to 28 years. All tumors (9/9) displayed microsatellite instability, with the half losing hMSH2 or hMLH1 expression. In the 5 genetic analyzed kindreds 3 possessed germline mutation. Two of three mutations have not been reported in the worldwide database previously. CONCLUSION: HNPCC showed distinct clinicopathological characteristics. Microsatellite instability analysis and immunohistochemical staining might be the effective screening methods before direct DNA sequencing for the detection of mutation in mismatch repair genes. It is important to analyze the members of affected families.
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Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Proteínas de Unión al ADN/genética , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Adaptadoras Transductoras de Señales , Adulto , Anciano , Proteínas Portadoras , China , Neoplasias Colorrectales Hereditarias sin Poliposis/metabolismo , Neoplasias Colorrectales Hereditarias sin Poliposis/patología , Análisis Mutacional de ADN , ADN de Neoplasias/química , ADN de Neoplasias/genética , Proteínas de Unión al ADN/análisis , Salud de la Familia , Femenino , Humanos , Inmunohistoquímica , Masculino , Repeticiones de Microsatélite/genética , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL , Proteína 2 Homóloga a MutS , Mutación , Proteínas de Neoplasias/análisis , Proteínas Nucleares , Proteínas Proto-Oncogénicas/análisisRESUMEN
OBJECTIVE: To discuss the value of multiple-slice spiral CT diagnosis of atypical intraabdominal hernia. METHODS: The clinical and CT findings of 16 cases of atypical intraabdominal hernia confirmed surgically were retrospectively analysed. RESULTS: In all the 16 cases, the contents of hernia were small bowels and the mesentery. Nine cases were caused by the adhesion after abdominal operations or infection, 6 by the mesenteric foramen, and 1 by the gap of pelvic peritoneum. The main CT findings were as follows:(1)the obstructed small bowels gathered abnormally and showed cluster shape(9 cases); the walls of the bowels thickened with edema and showed "target" sign with exudate in the neighboring spaces(5 cases); other part of the abdominal cavity became empty for lack of small bowels(4 cases).(2) Abnormal arrangement of the branches of mesenteric vessel, which appeared gathered or pulled or rigid and displacement of the main branches to left or right(12 cases). Thickened mesenteric vessel (4 cases): torsion of mesentery with "whirlpool" sign (3 cases). (3) With the help of multiplanar reformation, 5 cases showed the evidence of hernia rings. In the ring area, there were gathered or pulled or rigid and radiating mesenteric vessel and the dilated or effusion bowels in cluster arrangement forming "parachute" and "bundle of balloons" sign. CONCLUSION: CT manifestations of atypical intraabdominal hernia has some specific characteristics, which is of important value for clinical diagnosis and treatment.
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Hernia Ventral/diagnóstico por imagen , Tomografía Computarizada Espiral/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Among the most important of chemical intermediates are the carbenes, characterized by a divalent carbon that generates low-lying biradical (triplet) and spin-paired (singlet) configurations with unique chemical reactivities. The "holy grail" of carbene chemistry has been determining the singlet-triplet gap and intersystem crossing rates. We report here the first high resolution spectra of singlet-triplet transitions in a prototypical singlet carbene, CHCl, which probe in detail the triplet state structure and spin-orbit coupling with the ground singlet state. Our spectra reveal a pronounced vibrational state dependence of the triplet state spin-spin splitting parameter, which we show is a sensitive probe of spin-orbit coupling with nearby singlet states. The parameters derived from our spectra, including a precise determination of the singlet-triplet energy gap, are in excellent agreement with recent ab initio calculations.
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We report the first observation of iodocarbene (CHI) using fluorescence excitation and emission spectroscopy, which indicate a singlet ground state and a lower bound to the singlet-triplet gap of 3.76 kcal mol(-1).
RESUMEN
We have recorded stimulated emission pumping (SEP) spectra of the A1A' ' 1A' system of CHF, which reveal rich detail concerning the rovibronic structure of the 1A' state up to approximately 7000 cm-1 above the vibrationless level. Using several intermediate A1A' ' state levels, we obtained rotationally resolved spectra for 16 of the 33 levels observed in our previous single vibronic level (SVL) emission study (Fan et al., J. Chem. Phys. 2005, 123, 014314), in addition to one new level. An anharmonic effective Hamiltonian model poorly reproduces the term energies even with the improved set of data because of the extensive interactions among levels in a given polyad (p) having combinations of nu1, nu2, nu3, which satisfy the relationship p = 2nu1 + nu2 + nu3. However, the precise A rotational constants determined from the SEP data were invaluable in clarifying the assignments for these strongly perturbed levels, and the data are well reproduced using a multiresonance effective Hamiltonian model. The derived vibrational parameters are in good agreement with high level ab initio calculations. The experimental frequencies were combined with those of CDF to derive a harmonic force field and average (rz,r(z)e) structures for the ground state.
RESUMEN
Building upon our recent observation of the gas-phase electronic spectrum of the iodomethyl cation (CH2I+), we report an extensive study of the electronic spectroscopy of CH2I+ and its deuterated isotopomers CHDI+ and CD2I+ using a combination of fluorescence excitation and single vibronic level (SVL) emission spectroscopies. The spectra were measured in the gas phase under jet-cooled conditions using a pulsed discharge source. Fluorescence excitation spectra reveal a dominant progression in nu3 (C-I stretch), the frequency of which is markedly smaller in the upper state. Rotational analysis shows that, while the A constant is similar in the two states, the excited state has significantly smaller B and C constants. These results indicate a lengthening of the C-I bond upon electronic excitation, consistent with calculations which show that this transition is analogous to the well-known pi-pi* transition in the isoelectronic substituted formaldehydes. SVL emission spectra show progressions involving four of the six vibrational modes; only the C-H(D) stretching modes remain unobserved. The vibrational parameters determined from a Dunham expansion fit of the ground state vibrational term energies are in excellent agreement with the predictions of density functional theory (DFT) calculations. A normal-mode analysis was completed to derive a harmonic force field for the ground state, where resonance delocalization of the positive charge leads to partial double bond character, H2C+-I <--> H2C=I+, giving rise to a C-I stretching frequency significantly larger than that of the iodomethyl radical.